This invention relates generally to apparatus and methods for suctioning body fluids. More particularly, it relates to apparatus and methods for reducing the likelihood of contamination and infection during the collection of fluids from body cavities of human and animal subjects by suctioning fluids and disposing of or reusing those fluids without exposing the apparatus, the subjects or the collected fluids to potential sources of contamination and infection.
In modern medical practice it is often necessary or desirable to initiate drainage from body cavities in patients and to collect and contain these body fluids. In such situations, it is essential to prevent undesirable microorganisms from gaining access to both the drained cavity and to the collecting reservoir. It is also necessary to prevent undesirable microorganisms from gaining access to the collected fluids when those fluids are to be reused rather than discarded. By enclosing and preventing contamination of the collecting reservoir, the likelihood of retrograde contamination of the patient and cross contamination of the patients and hospital personnel is greatly reduced.
Unfortunately, conventional, commercially available, drainage devices are a prime source of infection in catheterized patients. For example, in the area of bladder drainage, a large proportion of catheterized patients suffer from urinary tract infections attributable to contaminated drainage devices. In most cases, the drainage collection device itself becomes contaminated in use and infection then ascends in a retrograde manner from the drainage collection device to the patient via the drainage catheter. Such retrograde infection from contaminated drainage or infusion devices has been observed, for example, in patients undergoing urinary, wound, biliary, gastro-intestinal drainage, peritoneal dialysis, and hyperalimentation treatment. See, e.g. E. M. Goldberg, et al., "Peritoneal Dialysis", Dialysis and Transplantation, June/July 1975, Vol. 4 #4; J. H. Isaccs, et al., "Foley Catheter Drainage Systems and Bladder Damage", Surgery, Gynecology & Obstetrics, May 1971, p. 889; R. E. Desautels, "The Causes of Catheter-Induced Urinary Infections and Their Prevention", J. Urology, 1969, 101:757; R. E. Desautels, et al. "Technical Advances in the Prevention of Urinary Tract Infection", J. Urology, 1962, 87:487; R. E. Desautels, "Aseptic Management of Catheter Drainage", New Eng. J. Med., 1960, 263:189; E. H. Kass, et al., "Prevention of Infection of Urinary Tract in Presence of Indwelling Catheters", J.A.M.A. 1959, 169:1181; and E. H. Kass, et al. "Entry of Bacteria into the Urinary Tracts of Patients with Inlying Catheters" New Eng. J. Med., 1957, 256:556.
Contamination of drainage collection devices often arises from containers or reservoirs designed to be filled repeatedly with drained body fluid and regularly emptied so suction can be resumed. For example, the evacuator described by McElhenny in U.S. Pat. No. 3,115,138 includes a capped fluid outlet. After the evacuator becomes filled it is emptied for reuse by removing the cap and expelling collected fluid via the outlet. During this operation the interior of the evacuator is exposed to the atmosphere and contamination of the evacuator will result.
Efforts have been made to reduce the contamination of drainage devices during periodic emptying. For example, U.S. Pat. Nos. 3,779,243 and 3,774,611 disclose evacuators which employ a special valve over the fluid outlet. This valve operates to close the outlet at all times except for the time when fluid is actually being purged from the evacuator. Such evacuators may succeed in reducing the contamination brought on by purging. However, since these evacuators must be periodically opened for purging, they are exposed to the surrounding atmosphere and will become contaminated and therefore a potential source of infection.
U.S. Pat. No. 4,435,171 for Apparatus to Be Worn And Method For Removing Fluid From A Living Subject, describes a closed, gravity drainage system designed to minimize retrograde introduction of microorganisms into a patient. This system, however, has no provision for suction drainage.
U.S. Pat. No. 4,265,243 describes one very complex liquid collection receptacle assembly in which urine is drained from a patient's bladder under the force of gravity into an intermediate collection chamber from which it is emptied into a larger receptacle either by siphoning or by squeezing the first chamber to force the urine from it. This apparatus, unfortunately, is most complex, and, as a gravity system, lacks the ability to suction fluid from the bladder or any other body cavity.
To the best of the present inventors' knowledge, no commercially available so-called "closed drainage" system is a "truly" closed drainage system. All current commercially available drainage systems were originally developed to avoid open drainage by enclosing the drainage through the catheter into a receptacle. The receptacle in all such systems is periodically emptied, opening the system up to potential contamination.
In modern medical practice, it is often desirable to efficiently collect blood, gastric, biliary, pancreatic, small bowel (succus entericus) and other bodily fluids into safe, economical containers, so that the fluids can be reused and returned if and when needed. In fact, with the widespread concern such diseases as acquired immune deficiency syndrome, which can be transmitted by the transfer of bodily fluids, it is particularly desirable to be able to collect blood from an individual, filter that blood as necessary to remove clots, particles, foreign bodies and microorganisms and then either store or immediately return the blood to that individual. Whether or not the collected fluids are to be administered to the patient from whence they came or to another patient, it remains essential to prevent contamination and infection from reaching the collected fluid.